Original article written by Chief Instructor Colin Hoad for nurburgring.org.uk.
Colin Hoad is a motor industry driver trainer and has been visiting the Nordschleife for business and pleasure for the last 11 years. He is chief instructor at CAT Driver Training. He writes for Evo magazine and is recognised as one of the leading industry vehicle dynamics trainers in the UK. He has kindly agreed to share his views on driving the Ring in the wet. Based at the Millbrook Proving Ground in Bedfordshire UK CAT offers half and full day Nurburgring preparation courses using the infamous Alpine Circuits.
Driving the Nurburgring in the wet
Driving the Nurburgring in the dry is challenging enough but what happens if it’s raining? The challenge for some is often a step too far. Read on for some enlightening and perhaps life saving advice.
What’s all the fuss about?
If you are planning your first trip or have only driven the ‘Ring in the dry you may be wondering what all the fuss is about – surely a wet road is a wet road? In order to drive quickly and safely at the ‘Ring in the wet you need to reprogramme your expectations of the available grip the tarmac offers when wet.
The circuit is used extensively throughout the year for motor racing, motor industry pool and tourist days. The net result: you are circulating on a highly polished unpredictable surface. In addition, when it rains the emulsified tyre rubber, oils and chemicals rise to the surface. No longer locked into the bedrock of the tarmac, they create grip levels you would normally associate with winter driving – even in the summer. Those that drive there regularly often quote the term “summer ice”, such is the lack of grip in the wet. Recent circuit improvements have seen many corners re-laid with new tarmac which has helped. But beware of the changes in grip as you transition over a tirade of differently shaded tarmac. Drive a steady lap and count the number of changes in surface – it may surprise you. I did it in 2002 and discovered 61!!
It is feasible to drive a lap of the ‘Ring and experience a multitude of weather conditions. If you have track day experience from other circuits, you must recalibrate your safety margins. It is realistic to suggest if you string two laps together, you could be finishing lap 1 with dry high G tarmac at Tiergarten, only to be confronted with rain soaked tarmac at the Hatzenback. If ignored this simple fact is enough to have you off and into the barriers. Constant assessment of the weather and track conditions is imperative. If you begin a lap on a wet or dry circuit, expect the conditions to change – you are out there for 14 miles in a mountainous region.
Keep an eye on Your mirrors
I would recommend vigilant use of your mirrors throughout the lap. Could a spin result in another vehicle driving into you? If you are finding your way around and learning the line, temper your speed until you are confident you know what challenge is coming next. It would not be good to spin on a blind brow with a snake of fast cars behind you. Be prepared to move out of the way and make space around you.
How well do you know the ‘Ring?
Is it your first visit? Are you a seasoned regular? If you are new to the ‘Ring it will take you 50 to a 100 laps to know your way around. It is also helpful to take some training if available. An experienced instructor will give you reference points to work with. The ‘Ring has many: from painted dots on the circuit; to KM markers; beginning and ends of barriers; and kerbs are all used to aid safety at speed and perfect each lap.
Is there a wet and dry line?
Technically yes, but let’s put some logic to the question. If you have logged many laps and are comfortable with what you perceive to be the optimum line in the dry, then I would suggest it may be time to explore a wet line. However, if you are new to the ‘Ring it would probably be an unrealistic objective to find a wet line over a dry line, as it is unlikely you will have built up enough track knowledge to define the differences and execute them at speed. For this reason as with any track, build your speed up slowly. Only you can decide if you are accomplished enough to go searching out a quicker alternative wet line. It may be safer to drive the dry line that you know at lower speed if it is wet, than go for the wet line and risk a mistake.
As a general rule in the wet you are searching out the parts of a circuit that have not been polished and therefore, contaminated, with rubber and chemicals that reduce the coefficient of friction between the tyre and the road so significantly. Avoiding dry line apex and clipping points is sound advice, positioning your vehicle “off line” if safe to do so, may find you more grip. I say “may” because if you take the case of the ‘Ring I think it is the exception to the rule! (There’s a surprise!)
Why? Go and spectate at the ‘Ring for a VLN Race or a busy tourist day and you will find many drivers spend time off line, letting faster vehicles pass. The circuit is narrow, granted, but how many times have you been committed for a corner and then found an over enthusiastic driver wanting to go faster, has nibbled away at your piece of tarmac and forced you off line? Or forced you to turn in later than you wanted?
In addition, how many new drivers each session drive the circuit just off the optimum line because they have not learnt the circuit? I have sat with drivers who have completed several 100’s of laps but not been trained and are therefore, not aware they are driving an inconsistent or incorrect line. So can you be sure that the wet line you think will be quicker and safer actually is? In my experience no you can’t.
Oil spillage – a hidden danger
The circuit as we know is maintained to the highest standards. Oil spillage is dealt with efficiently and effectively. I witnessed an oil leak from an ageing Rover SD1 that started at Exmule and finished just after Bergwerk. The driver realising he was losing fluid pulled off of the racing line and proceeded to drive until the sump must have emptied and the engine cried “enough”. Although dealt with immediately, the cement dust that absorbs the oil had all but disappeared by 5pm. I would not like to be on a motorbike when the next rain shower falls, especially if I was practising my wet lines. Be careful!
In the dry there are several kerbs that can be used to reduce your lap time and aid the dynamic stability of your vehicle, by taking the straightest line possible through a turn. Be aware if you hit a high kerb at speed: you can experience pad knock back and a momentary longer travel on your brake pedal than you expected. Why? As the wheel assembly and stub axle are flexed with the impact, the disc attached to the hub is also flexed, pushing back the pistons in the brake calliper. This can be very uncomfortable at the next corner when you have to pump up the brake pedal to slow down. Perhaps that should read heart stopping!
If it is wet, I would advise you stay off of the kerbs. If you are racing you may disagree, but if you are there for fun weigh up the risk. They can be slippery and unpredictable to drive on.
Stop, stop, stop!
We have discussed wet lines for the corners but what about the straights? The braking zones can be just as challenging at speed as the corners. Adverse cambers, settlement and differing split grip surfaces can all affect your vehicle stability when braking. You need to know if the vehicle you are driving is set up for the conditions. Can you adjust damper or anti-roll bar settings to increase your enjoyment and safety? Your wheels need to be a little more compliant with the road when it is raining.
Know your vehicles dynamic capability before you leave home, don’t leave it to chance. The ‘Ring is not the place to experiment unless you are a professional or have good track knowledge. Also, if you have adjustable dampers, ensure they are set correctly front to rear and side to side. We check these settings when training with clients at Millbrook and I have lost count of the cars we have adjusted prior to training due to imbalanced settings.
Are Your tyres up to it?
If it is raining heavily you will find rivers appear across the circuit and standing water in many areas. The potential to aquaplane at speed is real and to be expected. Ensure that your tyres have enough tread on them to clear standing water. Be prepared to adjust your terminal speed to reduce the likelihood of losing control – especially if the car you are driving does not have aero. If you are using semi slicks, for example 888s or A048s, they will be hard-pressed to clear standing water, especially if they are at the end of their life.
Take care and have fun
Yes, as with any circuit there is an optimum wet and dry line around the ‘Ring. Both can be learnt and experienced safely. Be sensible if you are new to circuit driving, new to the ‘Ring or both. Make your objectives achievable. The complexities of the ‘Ring’s characteristics can make the golden rules of track driving a little fuzzy around the edges.
Keep safe and enjoy your time at the ‘Ring.
Chief Instructor CAT Driver Training